This invention pertains to the art of valves and more particularly to pinch tube type valves or faucets.
The invention is particularly applicable to dispensing liquids from containers having an elongated flexible outlet tube disposed at the bottom end thereof and will be described with particular reference thereto; however, it will be appreciated by those skilled in the art that the invention has broader applications and is equally applicable to any number of other liquid dispensing environments.
It has recently been found that it is extremely desirable to dispense certain liquids from a large liquid reservoir into smaller containers for use or consumption. A typical and merely exemplary specific environment of this situation is the case of serving wine in restaurants. It has been found that many persons would purchase wine during a meal if it was made available by the "glass" instead of only by the "bottle". In an effort to increase wine sales in this particular type of environment, a system has been devised whereby wine is dispensed from a reservoir arrangement and then sold by the glass. In this system, the wine is stored in flexible plastic bag-like containers which include an elongated flexible or pinch tube extending outwardly from the lowermost end thereof. A full bag or container is inserted into a chiller or cooler arrangement with the pinch tube passing outwardly therefrom through a valve arrangement in order that wine may be conveniently dispensed from the bag as needed. Although the problems and advantages which the subject invention recognizes and overcomes were first apparent in this particular environment, it will be appreciated that it is readily adapted to use in other environments for any type of liquid dispensing where it is desirable to employ a pinch tube dispensing arrangement.
Since in most pinch tube liquid dispensing arrangements of this general type liquid flows from the pinch tube by operation of gravity, it has heretofore been extremely difficult to determine the exact arc or flow characteristics of the liquid as it exits the outlet end of the pinch tube since they continuously vary dependent upon the head of liquid remaining in the liquid container. Although a number of pinch tube type valves have been previously developed and employed in similar environments, these prior valves have not solved the operational problems encountered in their use due to changes in the flow characteristics of the liquid issuing from the outermost end of the pinch tube. Normally, prior valves merely received and maintained the associated pinch tubes in "straight-line" configurations without any attendant consideration given to the angle of departure of liquid from the end of the tube. When this angle was any angle other than vertical, undesired liquid spillage occurred during liquid dispensing due to simple miscalculations as to the flow path or arc of the liquid stream. Such spillage is costly, from the standpoint of unrecoverable loss of liquid, as well as unsightly and messy from a housekeeping standpoint. This particular problem is further increased by the fact that prior pinch tube type valves have loosely held the outermost end of the tube so that it was easily moved or jarred to even further modify the liquid flow characteristics. Previous attempts at controlling the liquid flow path or arc by manipulating the location or direction of the pinch tubes has resulted in undesirable kinking and binding of the tubes which led to corresponding liquid flow restrictions. These very same problems are also found in pressurized liquid systems where pinch tubes and pinch tube type valves are utilized.
In the environment to which the subject invention is particularly adapted, the liquid containers are periodically replaced when they are emptied with new, full containers. This, of course, requires removal of the pinch tube associated with the empty container from the pinch tube valve and insertion of the pinch tube associated with the new full liquid container into association with the pinch tube valve. Normally, this requires "threading" the pinch tube along a narrow passage and has heretofore been made very difficult because of the length of the passageway and the close tolerances required between the outside diameter of the tube and the inside diameter of the passageway. These close tolerances were required primarily because of the specific operational nature of prior pinch tube type valves.
Another problem which has been previously encountered with prior pinch tube valves in pressurized liquid systems has been one of liquid leakage through the valves. Since the basic concept behind such valves is one of "pinching" closed an elongated flexible tube along a portion thereof to control liquid flow therethrough, it has been difficult to design an easily threadable valve in which there would not be some liquid leakage through the pinched off area.